This invention relates to an improvement in the method of manufacture of friction clutches of the type employed in automotive vehicles, and more particularly to a method for precisely and rapidly adjusting a plurality of bosses fixed to the inner ends of associated clutch release levers.
In the prior art, adjustment of the release levers during assembly of the clutch has presented a continuing problem. Many ingenuous techniques have been employed but most of them have been expensive and cumbersome to carry out. It is well understood by those skilled in the art that release levers in the clutch of an automotive vehicle must have durable wearing surfaces provided near their respective inner terminal portions. The respective wear surfaces must all lie in a common plane so that the release bearings associated with the clutch will engage the release levers uniformly and simultaneously. Such operation is necessary to insure that the pressure plate is maintained in a plane parallel to the flywheel, whereby excessive wear will be eliminated, and the release of the clutch will be efficient and complete.
The variety of methods employed to achieve coplanar operation of the release lever inner portions have been unsuitable in the mass production of clutches. Such methods have lacked both economy and convenience. For example, in one instance, the outer tail portions have employed adjustable threaded screws with jam nuts for locking thereon for use in connection with associated bosses on the back side of the pressure plate. Another method has employed adjustable rivets requiring the added step of checking heights of the heads thereof with micrometers or dial indicators prior to the locking of the rivets into individual positions.
To the extent that such release lever inner portion adjustments are absolutely essential for proper operation of the clutch assembly, those adjustments heretofore have been necessarily carried out with great care and attendant expense.